True. But the diminutive University of California at Santa Barbara history professor knows much about a far more intriguing scandal that has daunted investigators for 300 years - the identity of The Man in the Iron Mask.Sonnino, a professor of Western civilization and early modern European history, is committed to solving the riddle and explaining why a hapless soul was imprisoned for 34 years on direct orders from King Louis XIV.

Though popular culture and the new Leonardo DiCaprio film, "The Man in the Iron Mask," have obscured historical facts by suggesting the prisoner was Louis' twin brother, Sonnino knows better.

"That's absolutely absurd," Sonnino, 67, said of the creative yarn first developed by Voltaire and embellished by French adventure writer Alexandre Dumas.

Fables are the things of fiction writers and moviemakers, not the work of investigative historians, Sonnino believes.

"One way to teach and study history is to develop a capacity to deal with evidence and to look at it critically," Sonnino said as he displayed a mountain of documents he uncovered during half a dozen trips to various archives throughout Europe.

These papers, which date to the early 1600s, are the recorded acts of common folks, French noblemen and ministers and associates to the king. They speak volumes about French society under Louis XIV, and, more importantly, they name names.

Sonnino has used the records to track the activities of Louis XIV's inner circle - the very people who could know the kind of damaging secret that would send a person to the Bastille.

Sonnino has searched for proof of the masked man's identity since 1989. The quest led to several suspects. Painstaking research has cleared all but one.

The likely victim of Louis' rage, according to Sonnino and a number of other scholars, was a valet named Estache Dauger. Historical records suggest Dauger was captured and imprisoned in 1669. He remained confined in various jails across Italy and France until his death in 1703 inside the notorious Bastille.

Interestingly enough, there are no records at all to suggest the long-suffering prisoner ever wore an iron mask.

"The only record that suggests the prisoner wore an iron mask is about as credible as a recent sighting of Elvis Presley," Sonnino said.

At best, according to historians, Dauger was made to wear a velvet covering when he was moved to the Bastille in 1698.

Why Dauger was singled out for such elaborate punishment is one of the missing links that Sonnino hopes to uncover when he returns to Paris this summer for additional research.

According to Sonnino, Dauger was no nobleman, let alone Louis' brother as Voltaire suggested.

"Voltaire was a publicity hound," Sonnino said of the famed thinker who was once jailed in the Bastille himself. "He claimed he knew everything and said The Man in the Iron Mask was the king's brother."

Dumas, a historical novelist who penned adventures about The Three Musketeers, took the rumor to new heights by conjuring a story about the king's tormented twin.

In truth, according to Sonnino, Dauger was a "flunky," who was punished for blabbing about the secrets of his betters.

"He was a gofer," Sonnino said. "Back then, servants did dirty jobs for people. He was the type of person Kenneth Starr would love to call before a grand jury, because he knew something that was not just hot air."

The French monarch could have had Dauger killed but instead ordered him imprisoned. The royal orders came with elaborate instructions that prevented Dauger from mingling with other prisoners or ever speaking about his past, according to Sonnino.

Sonnino said he has uncovered the secret that Dauger took to his unmarked grave. But the coy professor won't discuss the mystery in public until every hole in the theory is closed.

"I don't want to be remembered as the last in a long line of crackpots who claimed they had the right answer only to find out later I was wrong," Sonnino said.

The key, or "smoking gun," as Sonnino called it, may involve Dauger's unknown employer. If Sonnino can identify the valet's employer, he may be able to trace that man's actions through archival records. With luck, Sonnino hopes his search can verify his suspicions and perhaps solve one of the world's lasting mysteries.

Sonnino admitted that he may never solve the case, but like all who seek the truth, he sleuths on.

"This is an intellectual challenge," Sonnino said. "We are all curious about our pasts. We want to remember things as carefully as possible. It's a common human desire to find things out."